miRNAs in liquid biopsy for oral squamous cell carcinoma diagnosis: Systematic review and meta-analysis

Oral squamous cell carcinoma (OSCC) is often diagnosed at advanced stages and is associated with poor survival rates. Increasing evidence suggests that microRNAs (miRNAs) present in liquid biopsies could be potential biomarkers for non-invasive OSCC diagnosis. Here, we performed a comprehensive meta-analysis to evaluate the overall diagnostic accuracy of blood and salivary miRNAs in detecting OSCC. A literature search using PubMed EMBASE, Web of Science, LILACS, Scopus, and the Cochrane Library was undertaken up to February 2019. Study quality was assessed with the Quality Assessment for Studies of Diagnostic Accuracy-2, and sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and their corresponding 95% confidence intervals (CIs) were calculated using a bivariate random-effect meta-analysis model. Meta-regression and subgroup analyses were performed to assess the heterogeneity. Twenty-five study units from 16 articles with 2562 subjects were included in this meta-analysis. The pooled sensitivity and specificity of blood and salivary miRNAs in the diagnosis of OSCC were 0.78 (95% CI: 0.76-0.80) and 0.82 (95% CI: 0.79-0.84), respectively, and the pooled positive and negative likelihood ratios were 4.31 (95% CI: 3.38-5.51) and 0.25 (95% CI: 0.20-0.32), respectively. The overall area under the curve was 0.91 (95% CI: 0.88-0.93), with a diagnostic odds ratio of 21.46 (95% CI: 13.37-34.45). These findings provide evidence regarding the potential clinical application of blood and salivary miRNAs as a novel, non-invasive, and accurate diagnostic tool for OSCC.